Oscillatory mixing apparatus

ABSTRACT

An orbitally oscillating mixing apparatus unit for fluent solid material such as foundry molding materials comprising an orbitally oscillated support for a vessel providing a mixingspace-enclosing wall perpendicular to the plane of support oscillation, and a series of spaced blade-like elements secured in the vessel to oscillate therewith, which are elongated perpendicular to the support and located and spaced on a common circular or elliptical curve with a somewhat rotary impeller-like configuration in a set cooperating in action on material as a mixing device; the widths of the blades having generally similar angular dispositions between radial and tangential to the curve, and slanted outwardly in the direction of orbital oscillation, whereby in addition to a main circulating flow induced in material in the vessel opposite to the orbital oscillation direction, the mixing device acts to set up a circulating flow in a path within the device and having also a component parallel to blade elongation, by deflecting on respective blades portions of material from the main flow path inwardly to a region of recombination within the mixing device, there being a constant exchange of materials between the two flow paths. Plural mixing devices within a vessel, plural apparatus units on a common support with feed from one to another, continuous and batch type apparatus, and both horizontally and vertically orbiting apparatus are disclosed.

United States Patent 1 in] 3,894,721 Boenisch July 15, 1975 OSCILLATORYMIXING APPARATUS [57] ABSTRACT [76] Inventor: Dietmar Boenisch,Morillenhang 45, An Orbitall) osclllaling mixing apparatus unit for 5[ Ah Germany ent solid material such as foundry molding materials com risinan orbital] oscillated su port for a vessel [22] plied: May 1974 prov iding a mixing-spa ce-enclosing vFall perpendicular [21] App] No.:469,399 to the plane of support oscillation, and a series of spacedblade-like elements secured in the vessel to os- Related Apphcauon Damcillate therewith, which are elongated perpendicular l lCOMiHUHIiOH-iD-Pa" of Sci Nov 7 1 y to the support and located andspaced on a common 1972- circular or elliptical curve with a somewhatrotary impeller-like configuration in a set cooperating in action [30]Foreign Application Priority Data on material as a mixing device; thewidths of the July 26, 1971 Germany 2l37277 blades having generallysimilar angular dispositions between radial and tangential to the curve,and l l US. Cl. 259/2; 259/29; 259/5 slanted outwardly in the directionof orbital oscilla- 259/72 tion, whereby in addition to a maincirculating flow {51] Int. Cl. BOlf 11/00; BOlf l5/O2 induced inmaterial in the vessel opposite to the or- [58] Field 01' ear h 59/2,[2, 29, 54, 56, bital oscillation direction, the mixing device acts toset 259/72, 75, 80, 76, 63, DIG. 42 up a circulating flow in a pathwithin the device and having also a component parallel to bladeelongation, [56] References Cited by deflecting on respective bladesportions of material UNITED STATES PATENTS from the main flow pathinwardly to a region of re- 2,l43,6|0 1/1939 Muller 259/2 CombinatioWithin the mixing being a 2340923 7/|958 Behrens 259/72 constantexchange of materials between the two flow 3,l84,222 5/1965 Arondwitz 5t 259/72 P aarpenko i Y Plural mixing devices within a vessel, pluralapparatus oore i 3,430,926 3/1969 Freedman 259/54 umts common supper Wnhfeed from one to Primary ExaminerRobert W. Jenkins Attorney, Agent, orFirmP. D. Golrick another, continuous and batch type apparatus, and bothhorizontally and vertically orbiting apparatus are disclosed.

18 Claims, l4 Drawing Figures "."Ti-Ti" I 1 m. 1 5 13. 5

SHEET FIG. 3

FIG. 4

OSCILLATORY MIXING APPARATUS This application is a continuation-in-partof parent copending US. patent application Ser. No. 274,762, filed July24, 1972, the disclosure of which are herein incorporated by reference.

This invention relates generally to improvements in apparatus for mixingmaterials, particularly foundry molding materials, by an orbitallyoscillating vessel having therein a fixed mixing device, and whereby twoor more circulating currents are established with a continual mixingexchange between said currents.

In various industrial processing technologies there is a continuallyincreasing demand for short mixing times with efficient mixing ofmaterials involved in the processes. Particularly important for thefoundry industries in technical and economic aspects are the operationsinvolved for the mixing of molding compositions, wherein quartz sandsare ultimately bonded with a synthetic resin. Here the sand isintimately mixed with the resin and with added activators, catalysts orhardeners, the reaction of which, leading to a setting of the moldingcomposition should take place first or to high degree in the moldingflask rather than in the mixing apparatus. Obviously then fast thoroughmixing is highly important.

In the prior art various applications of oscillating, gy ratory ororbitally driven mixing vessels are known for the mixing of quitediverse liquid materials, particulate or granular materials, andcombinations thereof. The aforementioned pending application disclosesan orbitally oscillated upright cylindrical vessel, driven withfrequencies in the range of 1,500 to 10,000 cps, and having thereindisposed one or more mixing devices affixed to and cooperating with thevessel to develop flows or currents of material with horizontalcirculation and also vertical components to effect mixing between theflows.

By orbital vibration or oscillation, here is meant the movement ofabody, wherein each point thereof tends to move in a closed curved pathabout its respective distinct axis, but without any rotation of the bodyas a whole with all points thereof swinging coaxially about a commoncenter or axis.

The present invention is based first on the discovery that athree-dimensional array of elongated blades having, for example, apaddle wheel type configuration of blades as used in rotating impellersin air blowers or fans, e.g., for axial fan blowers, air turbines ortrans verse blower fans, is eminently well suited to mix the materialsin the shortest possible time, when arranged as a non-rotating butoscillating mixing device within a mixer vessel. This arrangement ofoscillating" blades is so effective that in many cases, particularlywith smaller mixer units, even with the mixer vessel stationary, it issufficient merely to vibrate or oscillate the blades as a mixing devicewith circularly or elliptically orbital oscillations about axesextending substantially parallel with their lengths. In such array theblades are arranged along a closed curve, e.g., a circular or ellipticalline, and at an angular disposition to the curve falling in a rangebetween tangential and radial thereto, with spacing and other bladedisposition variations as later detailed.

However, it is especially advantageous to oscillate the surroundingmixing vessel jointly with the blades by a common drive, as thisachieves a certain further cooperative mixing effect imparted by thecontainer walls, and a beneficial utilization of the drive. In this way,a quasi-fluidized bed" is created within the entire mixer vessel,promoting effective rapid mixing; and thereby also the mixed materialsare effectively prevented from sticking to the vessel walls.

Consequently, additionally to a major current or main circulatingmovement imparted to a quite fluid bed of material to be mixed by theoscillating vessel walls, the oscillating blades also impel thematerial, and respectively, continually split off from a major currentminor layer" currents or branch" currents, and direct them to recombinewith relative displacement to a region central of the blade set thereforming a new larger current. For this purpose it is particularlyadvantageous to provide more than two blades.

The current formed by recombination of the branch currents or layersderived from a main current is advantageously moved away in a directiondifferent from, and preferably at about relative to, that of the maincurrent from which derived for increasing mixing inten' sity by furtherturbulence. Thus, for example, from a main current circulating along thewall of an upright cylindrical vessel, a concentric array of oscillatingblades divert branch currents, and conduct them to a central regionwithin the array, that is, in a direction generally towards the axis ofthe oscillating vessel; and in that region in addition to other motion,a recom bined current advances also in the direction of the vessel axis.

The invention is more specifically explained relative to theaccompanying drawings presenting some practical embodiments. It ishowever, not confined to the illustrated embodiments and many furthermodifications are conceivable within the general scope of thisinvention.

It is the general object of the present invention to provide improvedapparatus for the mixing of fluent, principally particulate substancesor materials, such as foundry molding materials, whereby a more thoroughmixing, and even shorter mixing times are attained.

A more particular object is to improve mixing appa ratus of the typecomprising an orbitally oscillated mixer vessel with a mixing devicetherein.

Another object is to provide a mixer apparatus which has a simpleconstructional design and basically has no relatively moving mixingelements.

Another object is to provide a mixing unit arrange ment which isapplicable to batch mixers as well as to continuous mixers.

A further object is to provide at the same time a mixer which is rugged,largely maintenance-free and subject to little wear and tear.

Other objects and advantages will appear from the following descriptionand the accompanying drawings, wherein:

FIG. 1 is a top plan view of a mixer unit comprising an uprightcylindrical vessel and a mixing device emplaced therein;

FIG. 2 is a perspective and essentially diagrammatic illustration of avane or blade assembly comprising the mixing device according to FlG.1',

FIG. 3 is a vertical section taken along the line 3-3 in FIG. 1;

FIG. 4 shows a modification of the mixer vessel of FIG. 3, adapting theunit for core shooter and like use;

FIG. 5 is a top plan view of a modified mixer unit similar to that ofFIG. I;

FIG. 6 is a somewhat schematic representation of a continuous horizontalmixer unit with a mixer vessel of an elongated trough shape;

FIG. 7 is a top plan view of yet another upright mixer unit;

FIG. 8 is a top plan view of a further mixer apparatus;

FIG. 9 is a top plan view of yet another mixing apparatus embodying aseries of vessels and mixer devices similar to that of FIG. I, but withvessel modifications for continuous feed;

FIG. 10 is a perspective representation of a modification of the mixershown in FIGS. 1-3;

FIG. 11 is a top plan view of a mixing apparatus embodying a pluralityof mixer units each representing a modification of FIG. 10, to providecontinuous through feed of distinct mixing streams, with final totalmixing at a discharge point;

FIG. 12 is an irregular vertical section, taken principally along theline 12-12 in FIG. 11;

FIG. 13 is a top plan view of a further mixing unit modification;

FIG. 14 is a vertical section taken along the line 14-14 of FIG. 13.

In the following description of various mixer units or apparatusembodying the invention, generally only the basic dispositions of theprincipal components will be presented. Thus, with the exception of thedriving means and mounting outlined in FIG. 11-12 for providing theorbital oscillation here commonly used, which is to be understood asapplicable to the arrangements of the other figures of the drawings, thedriving means, loading and discharge facilities, oscillating apparatus,etc., usually are not specifically described inasmuch as they form partof existing knowledge or prior disclosures.

FIGS. 1-3 Basic Structure and Operation For the mixing apparatus unit ofFIGS. 1-3, in an orbitally oscillatable mixing vessel 10, an uprightcylindrical, flat-bottomed container, a series of six like elongatedflat vanes or blades 11 are arranged and secured to the vessel, equispaced along a closed conic (here circular) curve center line 12concentric with the vessel axis. The blades extend longitudinallysubstantially parallel to the vessel axis and are similarly located onthe circle, with widths extending at like angles in the range between atangential and radial disposition relative to said circle, so that herethere is a six-fold rotational symmetry about an axis of symmetry whichis the vessel axis.

The three-dimensional or spatial arrangement of the blades, as a setconstituting what will here at times be called a mixing device M,corresponds to the paddlewheel-like rotary impeller configurationfamiliar in certain types of air fans or blowers. Here the circularreference line 12 is a convenient projection representation of animaginary coaxial reference cylinder to which are referred the locationsof corresponding parts of the blades.

The blades here are secured to and extend from the vessel bottomlongitudinally parallel to the vessel axis V and the axis 14 of vesseloscillation, upwardly in the charge 13 of materials to be mixed; butthey also may be dependently secured to a vessel cover plate or lid toproject downwardly into the charge, preferably with lower ends spacedslightly away from the vessel bottom.

Individually, or assembled as a structural unit mounted within thevessel, the blades 11 are rigidly secured to the vessel by screws orlike fasteners, or by welding; or they may be formed integrallytherewith as a single casting. They may consist of metal, syntheticmaterial or rubber-coated metal, as may the vessel itself, dependingupon usual engineering design considerations.

The angular disposition of the blades defines between each adjacent paira passage or channel 15 in effect tapering or converging away from thecylindrically annular space defined between the vessel side wall and theouter vertical edges lle of the blades, or rather a cylindrical envelopeof those edges, to open inwardly to a vertically elongatedblade-enclosed region 16 interior of the blade inner vertical edges,conveniently considered as enclosed by the cylindrical envelope of thoseinner edges.

The vessel 10 and the mixing device rigidly secured thereto are set inhigh-speed orbital oscillation relative to a base by known means, suchas an eccentric drive, as described in said parent patent application oras exemplified relative to FIGS. 11-12, or by an unbalanced rotatingweight type drive.

For example, a counterclockwise eccentric rotation so drives the vessel10 that it does not rotate about its own axis V, but that axis orbits ona small radius about the vertical axis 14 of rotation of the eccentric,which is here termed at times the axis of oscillation. Indeed, everypoint in a horizontal cross section of the vessel similarly orbits abouta distinct vertical axis, as indicated in FIG. 1 for oscillation of thepoint B on the circle about axis line A; the diameter of which circle isdetermined by and is twice the drive eccentricity. Hence the walls ofthe vessel 10 and the mixing device M comprised of the blade set undergothese oscillations in the same manner.

With certain other useful drives the orbit may be elliptical and theresulting oscillation is comprehended in the term orbital oscillation.Such circular or elliptical oscillation is a pre-requisite condition forthe functioning of all mixer apparatus with mixing devices according tothis invention, and is to be understood as provided without a repeateddescription or representation thereof in discussing the individualexamples of practical applications of the invention.

Assuming counterclockwise orbiting, the fluent charge will tend tocirculate with a main flow in clockwise direction along a path in theaforementioned annular space, as shown by the arrow C. The rate ofadvancement or pumping of the material will increase with the diameterof the oscillation circle, i.e., with amplitudc, but will increaseparticularly with the oscillation frequency. Thus increased pumpingspeed means increased mixing speed. An oscillation drive rate of morethan 1,000 rpm, hence a frequency exceeding 1,000 cps, has been foundvery efficient to assure high mixing performance; and oscillationamplitudes of a few millimeters have been found quite adequate.

The continual high-speed oscillation of the mixer unit as a whole,including the mixing vessel and the mixer device, on the one handproduces a very loose flowable condition of the charge, akin to afluidized bed, owing to the rapidity of successive advance and retreatof the blades, and as well advances the material along the vesselinternal wall surface and along the blades which exert a considerableimpelling thrust.

The outer edge lie of each blade faces the direction from which thematerial approaches in flowing around the mixing device in the clockwisepath along the vessel internal wall, so that the blades scoop or shaverespective portions or upright layers from the main current or flow aslayered branch currents deflected, as though in a vortex, through thechannels 15, being rolled or turned inwardly to recombine under relativedisplacements thereof to form a further current internal of the mixerdevice, around the vessel axis V, in the middle region 16. In thisrecombined current, material is carried away also in an upwarddirection, as it were in an upward helical or vertical flow as shown inFIG. 3. Thus by virtue of the circular and upward components, moldingmaterial, which is flowing in a loose bulk condition engendered by theoscillation, continually emerges above and fans out away from theoscillating blades at the upper end of the mixing device to be scatteredexternally of the mixing device, (as also indicated by arrows in FIG. 3)over the top of the material circulating in the main flow path, wherethere is of course also a downward motion component involved. Thence itis redirected again inwardly and delivered upwardly by the bladed mixingdevice.

This continued high speed batch division and intermixing within andwithout the mixer device affords extremely high mixing efficiencywithout any movement of the mixer device within and relative to themixing vessel. The mixing principal and action is simple and at the sametime effective.

The internal space 16 enclosed by the blades or blade internal envelope,preferably should be smaller than the annular space defined assurrounding the device between the vessel wall and the external bladeenvelope. These conditions promote a higher velocity of flow for thematerials within the mixing device.

For achieving a high mixer performance and efficiency, the plane ofoscillation in the mixer device, as far as possible, is parallel withthe direction of deliv ery required of the oscillating blades. Since inmost cases the blades will be required. as in FIGS. 1-3, to deliver in adirection towards the mixer device interior 16, the plane of oscillationwill then be similarly disposed relative to or at right angles to thelongitudinal axis of the mixing device here coincident with that of thevessel. Inasmuch as the oscillating vessel and the mixing device eachoccupy space rather than a plane, the phrase plane of oscillation" isunderstood to mean an arbitrary reference plane perpendicular to thelongitudinal axis or center line of the vessel or of the device as thecase may be. For similar reasons, the axis of oscillation" of either,unless context dictates otherwise, signifies the axis about which thelongitudinal center line of vessel or device is orbiting.

The mixing efficiency depends to a high degree on the setting angle andthe width of the blades as well as on the gap width or relative spacingtherebetween, in the mixing device. Preferably the number of blades isincreased with the diameter of the vessel. A small mixer apparatus,having 5 litres capacity and the configuration of FIGS. 1-3, may managewith six blades as shown, for example, in FIGS. 1 to 4 and 10. The timesfor mixing to complete homogeneity, with frequencies as low as about3,000 oscillations per minute, have been obtained in a range from onlyto seconds.

Though not exemplified in any of the drawings, it is noted that theindividual blades ll may also be of upwardly tapering or twistedconfiguration or be inclined toward or away from the vessel axis, sothat the radial length of the channels 15 will be enlarged orconstricted along the direction parallel to the longitudinal axis of themixer device M, whereby the mixing device zones of entry and exit of thefluent material may be deliberately located in the regions of the mixingunit most favorable for effective mixing under given circumstances.

It is also possible to reverse the mixing flow pattern from that shownin FIG. 3, by closing the top of the mixing device with a lid andspacing it, i.e., the lower ends of the blades, away from the vesselbottom.

FIGURE 4 Pneumatically Discharged Apparatus The modification, orelaboration, of FIG. 4 represents a particularly advantageousarrangement for pneumatically discharging material from or emptying theoscillatory mixer apparatus. This is based upon specific advantageouspeculiarities of this invention, especially the fluidity condition ofthe material engendered by the high speed oscillation, and theconsequent very rapid delivery of material into the mixer deviceinterior 16, which create optimum conditions for expelling or aspiratingthe finished mixed batch from the vessel by compressed air orfan-induced suction,

For this purpose, at least during the emptying operation, the vessel 10must be closed comparatively airtight by a lid or cover 17 carrying acompressed air feed pipe 18, and, depending toward the bottom region ofmixer device space l6, a central discharge pipe 19. If desired. closablecharging ports may be included in the cover structure. With theapparatus unit maintained in the previously described orbitingoscillation, the finish batch will flow out through pipe 19, even atcomparatively low air pressures or pressure differentials and so may betransported directly to stations of further treatment or use.

Hence, for example, since the material may be expelled or air blasted inthe quickest and shortest way directly into molds or core boxes, a veryshort reaction time may be used for chemically setting foundry mold ingcompositions, comprising cold-setting mixtures of sand, resin andhardener. This obviously is highly advantageous as offeringcorrespondingly increased productivity. The eminently high flowabilityor fluidity of the molding material within the mixer while oscillatingwill produce adequate core strengths even at shooting" pressures ofabout 2 atmospheres, in contrast with pressures of about 5 atmospherescurrently normally used in conventional core-shooting machines. Thismeans, that less pneumatic energy is involved in operations. and thatthe shooting machines may be much simplified and lighter inconstruction.

In this application of the invention to provide a mixer unit functioningalso as a coreand mold-shooting machine for chemically setting foundrymolding material, a further important advantage arises; namely, theprevention of compactions or agglomeration of setting mixtures withinthe oscillating apparatus. Particularly, residual excess mixture leftover in the apparatus from the production of a given mold or core, whichwould inevitably cause blockage or constrictions in conventional mixers,is here prevented from baking or sticking together in the oscillatingapparatus, since it is con stantly being turned over or sheared by thenovel mixer device therein. Further, under the oscillatory impulsesimparted thereto, the individual sand grains remain separate till afterthe end of the chemical reaction, and consequently can be absorbedwithout any disadvantage whatsoever in a subsequently charged batch ofcomponents for a fresh mixture.

The basic elements of the mixing device, shown in and described for thebatch mixer unit of FIGS. 13, may be further adapted to specialrequirements by various possible modifications of which a few examplesare hereinafter described.

FIGURE 5 Whereas in FIGS. 13, the width of the interspaces or passagesbetween successive individual blades is generally constant frominterspace to interspace, it may be unequal for achieving special mixingaction or patterns, for example, as shown in the upright unit of FIGS.5-6 where the relative blade spacing is notably larger resulting in apassage or channel 21 of considerable width. This causes the materialimpelled through the other narrower channels 15a-lSd into the mixingdevice interior 16, whence it emerges in greatest part laterally (asindicated by the arrows 22) through the wide channel 21 and along nearlythe whole vertical length thereof to discharge into the surroundingannular space, rather than in the usually preferred manner, of axialemergence from the upper end of the mixer device, as shown in FIGS. 3,with discharge essentially above and across the surface of the rest ofthe mixture contained in the vessel.

FIGURE 6 Horizontal Continuous Flow Mixing Apparatus Though the examplesthus far described have presented mixing apparatus units with uprightcylindrical mixer vessels 10 and mixer devices M with verticallyextending mixing blades, the invention may also be ap plied tohorizontal apparatus, or generally horizontal, but somewhat inclinedapparatus, with the plane of oscillation correspondingly vertical ornearly vertical.

Thus in FIG. 6, a mixer device M, designed somewhat similarly to thatshown in vertical disposition in FIG. 5, is disposed horizontally in ahorizontally elongated trough-like mixing vessel 10A with asemi-cylindrical bottom 10b merging upwardly into vertical longitudinalside walls 10.\', preferably spanned by a top wall 101. The severalblades 11 extend over the whole of the vessel length to be rigidlysecured to the flat vessel end walls 10d at which the vessel isresiliently supported and driven (for example, analogously to the understructure in FIGS. 11-12) to oscillate in a vertical oscillation plane."as indicated by the point B and its oscillation circle about arespective axis A extending parallel to the trough centerline or axis.

Moreover to provide a continuous mixer unit, a charging inlet 23 isprovided at one end, which may be slightly elevated, as an inlet tubethrough a top wall 101 where used; through which individual mixturecomponents, such as sand, resin and hardener may be supplied by adispenser or supply device not here specifically indicated. A lateraldischarge pipe or conduit 24 is then located on a side wall 10A,remotely from the feed inlet.

With the assumed indicated orbital oscillation direction, as shown byarrows in FIG. 6, the individual blades 11 again deliver branch"currents of material inwardly towards the mixing device central region,from which in effect the device opens upwardly owing to the large gap(corresponding to the channel 21 in FIG. 5), representing in effect anabsence of blades in this direction; so that the mixed material emergesin this more or less upward direction along the length of the mixingdevice M. Again the material is continuously engaged and deflected bythe blade outer edges, from place to place along an outer main flowcirculating path adjacent the trough sides and bottom 10s, 10b, to bemixed again with an excellent mixing efficiency.

With constant feed additions at 23, the entire charge mass also moves asa whole longitudinally while being subjected to strong mixing action inthe arcuate currents or circulating flows, therefore helically throughthe mixer trough, ultimately to leave through the lateral discharge pipeor conduit 24.

Special advantages may be obtained by disposing several of thesecontinuous horizontal mixer units in a parallel arrangement. Thus forexample, sand and resin may be thoroughly pre-mixed in a first mixerunit, and sand and hardener in a second, so that no reactions can occurwithin the individual mixer troughs. The homogeneous pre-mixed materialsmay then be continuously discharged to and quickly intermixed in asimple postmixer device, such as a similar horizontal mixer.

FIGURE 7 Higher Capacity Batch Apparatus The upright batch mixers ofFIGS. 1-3, or 4 can effectively handle only moderate batch volumes athigher mixing speeds. However, operating on the same principles highercapacity mixers may utilize two or more mixer devices, arranged in acommon vessel laterally adjacent or within one another, in number asrequired for the batch size and for higher mixing speeds.

Thus in FIG. 7 what amounts to a more complex mixing device M-] isprovided in upright cylindrical mixing vessel 10, by two mutuallyinterfitted or coaxially arranged mixer devices consisting of a firstset M of blades arranged along the inner circle 12; and, arranged alongthe outer circle 26, a second set including a majority of flat blades11, but others 11a shown to be radiussed, i.e., curved in horizontalcross section.

FIGURE 8 Upright Continuous Feed Mixer Unit In FIG. 8, groups of blades,representing respective mixing devices M (each such as that of FIG. 1),are equally spaced as groups successively on a circle concentric withthe vessel axis, where another mixing device M is centered in theupright cylindrical vessel 10; the latter being orbitally oscillated asa mixer apparatus unit in the manner previously described. This unit asthus far described may be operated as a high capacity batch mixerapparatus.

However, the construction of FIG. 8 may be simply adapted for, and isshown as, a continuously fed mixer apparatus, by inclusion of a radiallydisposed vertical baffle or damming wall 28 extending over the fullheight of the cylindrical vessel wall and projecting therefrom inwardlybetween two adjacent mixing devices M, in combination first with adischarge trough at 29, or other delivery device, at an opening. e.g.,in the top margin of the vessel side wall counterclockwise of andclosely adjacent to baffle 28; and secondly with feed or supply inlettroughs or conduits 3t) and 31, lo cated on the clockwise side of dam28.

Owing to the oscillation of the wall 10, the general mass of thematerial will move clockwise in the direction of the arrows C-] from thesupply stations to encounter baffle 28 and discharge at outlet 29; withmixing action occurring locally at each of the mixing de vices M both inthe outer series along the path and also at the central device relativeto the flows C in the annular paths thereabout. The mixer apparatus willdeliver finished mixed material at a rate corresponding to the rate ofcomponent feed.

FIGURE 9 Continuous Feed Mixing Apparatus A high capacity, continuousfeed mixing apparatus of great mixing efficiency is obtained in FIG. 9by what is in effect a circular arrangement of several successivelycommunicating vertical cylindrical mixer units of the basic design shownin and previously described for FIGS. I-3 as a batch unit.

Therein what maybe considered 12 circularly adjacent mixer sections on acommon support, the intersecting mixing vessel cylindrical walls areinterrupted by vertical passages or openings 32a, 32b, 32c, etc.,excepting where the common wall 38 occurs between two adjacent sections,resulting in what is actually an annular vessel 36 with scallopedinternal and external walls. Mixture components are fed by supplyconduits or troughs at 33, 34, 35 into the mixer sections immediatelyclockwise of wall 38; and at 37 a lateral outlet through the vessel wallcounterclockwise of 38 has an associated discharge trough.

The entire unit with the several mixing devices M secured centrally inthe respective sections is orbitally driven and mixing occurs in eachsection generally as previously described. The fed material passes inthe as sumed direction of arrow C with thorough mixing at eachindividual mixing unit" successively through the whole vessel finally todischarge well mixed at 37. The mixing efficiency of such a continuousmixer apparatus increases with the mixing intensity of the individualmixer devices and with their number.

FIG. Mixing Device Modification In FIG. 10, a perspective schematicillustration, there appears a mixing device M-2 modified from thearrangement shown in FIGS. 1-3, by terminating the blades at their upperends at or in an annular member such as a short pipe or tube. Member 20prevents in the upper region of the mixing device that lateral or radialtransfer of material described by the shorter arrows below the bladetops in FIG. 3.

This arrangement intensifies the vertical component of the overallmixing circulation, inasmuch as the material is always stripped off fromthe flow in the annular space between side wall and mixing device at thelevel of the exposed blade edges in the mixer bottom region; and isdelivered upwardly therefrom through the length of member 20 either tobe scattered onto the upper surface of the material batch in the vessel10, where the FIG. 10 structure is used in a batch apparatus, or elsedelivered from the top of member 20 to a discharge chute or the likewhere the unit of FIG. 10 is used in a larger apparatus as nextdescribed.

FIGS. 11-12 Continuous Feed Parallel Mixing Apparatus In FIGS. 11-12,there is shown another apparatus incorporating the invention, which isespecially adapted for continuous feed mixing of a foundry moldingcomposition comprised of quartz sand, with a reactive binder resin andhardener.

Two series arranged in right and left hand rows of vertical cylindricalmixer units, each representing an elaboration of the type shown in FIG.10, are rigidly secured on a flat rigid horizontal round support member46, forming as shown (see FIG. 12) a common bottom for the severalvessels 10a, ltlb, lOc', in the right row 10d, lOe, lOf in the left row;the support member in turn being non-rotationally, but orbitallyoscillatably mounted through conventional sturdy resilient or elasticpost units P. The support 46 is orbitally oscillatorilly actuated by anelectric motor Em secured in the base Z and driving the eccentric in anappropriate eccentric bearing housing H secured to the bottom of thesupport plate 46.

The branches of a bifurcated sand supply chute or trough 40 feed intothe annular space about the mixer device of the respective first mixervessels 10a and 10d of the right and left rows. Resin and hardener feedpipes or conduits 41 and 42 likewise feeding into mixer vessels 10a and10d afford simultaneous supply of resin and hardener with the sand tothese vessels respectively.

As shown more clearly in FIG. 11, each bladed mixer device M-3 has threecurved mixer blades 11c, though at times two blades suffice, and, ifnecessary, more than three can be provided: and the rather stubbyannular member 20 of FIG. 10 here is modified to an elongated tubularriser 20a, bearing at its top end above the top of the vessel wall asloping lateral discharge chute 43. For sturdy simple mounting, theriser bottom end and blades are secured to the vessel floor. and theblades also to margins of riser side apertures.

Whereas the first two chutes 43 are relatively short to overhang thewalls to discharge into the annular space of the next unit, for thefinal units of each row the discharge chutes or troughs 44 and 44a areelongated to discharge into a final mixer vessel 45 which, in itsinterior, is equipped with similar mixer device (not shown). Preferably,as shown in FIG. 12, the final mixer vessel 45 has its own base anddrive; but it can also be secured to the support plate 46 to eliminatethe individual drive.

Within each mixer vessel, the material to be mixed moves upwardly withinthe blades 11c and the coaxial shaft formed thereabove by the riser 20a(as explained relative to 20in FIG. 10), and discharges from the risertop through the sloped trough or chute 43, to enter the annular spacebetween the vessel wall and the mixer device of the adjacent mixer unit.

In this way, the fed resin and sand are conveyed with mixing from mixervessel 10a to mixer vessel 10c, and the fed hardener and sand from 10dto 10f, resulting in preliminary mixed streams delivered from the thirdunits via chutes 44 and 44a for final mixing in 45; from which in turnby a like mixing device such as M-3 (not shown in 45) the finalcomposition is mixed and continuously delivered for use.

FIGS. 13-14 Instantaneous Continuous Mixer A very efficienthigh-capacity continuous vertical mixer apparatus is shown at FIGS.13-14 respectively in top plan and in vertical axial section.

In an external cylindrical upright housing 10x, there are located andembraced six like nearly cylindrical elements 11g each closed by abottom wall 39b. These elements may be conceived of as being as it were,each a longitudinally slotted tube with one reflected outwardly bentslot edge 1111; and with the tubular elements disposed in a circle withthe straight slot edge of each longitudinally engaging and preferablysecured to an outer surface of adjacent element at a line spaced fromits respective bent slot edge. By this disposition the elementssuccessively conjointly form vertical tubular or cylindrical chambers,each now having a quite narrow vertical outlet slot 15x opening into avertically elongated central space or region F functionally akin tointerior region 16 in a FIG. 1 type device. This central space (see FIG.14) preferably has a closed top 390 and a downwardly convergentfunnel-like bottom discharge opening 3a, in the housing bottom wall 39for gravity discharge. The unit is oscillated by means and in the mannerpreviously described about its axis.

Plan view FIG. 13 shows the resemblance to the basic type of FIG. 1,which can be considered to have merely been modified in that pairs ofmutually adjacent blades 113 are combined on the outside to present aclosed chamber having a rounded cross sectional configuration fordynamic flow reasons. In effect an element por tion from its bent slotedge 1 1h out to the line of attachment with the straight edge of acounterclockwise adjacent element, then continues in the latter as ablade which, at the wall of 10):, is then reflected inwardly to the leftto meet the next element.

By means of dispensing or conveying devices, (not here shown; e.g.,plastic tubes of larger diameter), components for the desired mixtureare continuously fed to the respective individual alternating mixerchambers D,E,D, etc.; for example, the chambers D receiving the supplyfeed of sand and resin, and the chambers E receiving the supplied sandand hardener.

Hence under oscillation the mixture components which emerge from D and Elayerwise through the loftgitudinal slots 151:, will continuallysuccessively overlap one another, and as shown by the spirals in FIG.14, will descend in a helical movement and be turbulently combined. Thiscontinuous vertical mixer with its drive unit may be convenientlymovable or portable, so that it may be moved to a spot directly adjacenta work station for filling a foundry mold box located therebeneath. Whenthis mixer serves as a final or post'mixcr apparatus for combiningpreliminary mixtures of sand with resin and of sand with hardener, thepreliminary mix tures may be prepared by using other continuous mixingdevices, e.g., those shown in FIGS. 6, 8 or 9.

This mixing apparatus is suited and preferred for damp or more or lesscohesive or adhesive components or pre-mixed materials, which will notrun or trickel out of narrow slots, when the mixer oscillation isstopped. It is suitable, for example, for the final or postmixing ofpreviously prepared sand-resin and sandhardener preliminary mixtures,because it will combine the preliminary mixtures only at the moment whenit is switched on, so that in the stationary mixer, there can be noappreciable chemical reactions.

A further important advantage derives from the fact that the furtherrunning in or supply of the prelimiinary mixtures is immediatelyinterrupted on switching the unit off, and the finished mixture willdrop out of the apparatus leaving no reactive residual mixture withinthe mixer. It is possible to extract instantaneously any requiredamounts of finished mixture in precisely measured quantities which arereadily available at all times. Hence, this type of mixer is excellentlysuited for special purposes, for example, in the foundry industry formaking molds and cores by the so-called cold-setting process.

What is claimed is:

1. An orbitally oscillating mixing apparatus unit for fluent soldimaterial, such as foundry molding materials, comprising: a supportmounted for, and driven with, an orbital oscillation in a plane,

a vessel secured on the support for oscillation therewith, and providinga mixing space enclosing wall substantially perpendicular to the planeof support oscillation,

a plurality of blade-like elements secured as a set to the vessel tomove therewith,

and elongated in direction away from the support, and located and spacedalong a closed conic curve the plane of which is parallel to the planeof oscillation, the widths of said blades having similar angulardispositions between radial and tangential to the curve, and slantedoutwardly toward the direction of orbital oscillation, said bladesthereby forming a set of somewhat impeller-like configurationcooperating in action on material as a mixing device, whereby, inaddition to a main flow induced in material in the vessel tending tocirculate in a path along the enclosing wall oppositely to the orbitaloscillation direction, the mixing device acts to set up at least asecond flow circulating within the device and having also a componentperpendicular to the plane of oscillation, by each blade deflectingmaterial, from a portion circulating in the main flow path, inwardly toa path of recombination within the mixing device and with a constantexchange of material between the two circulating flow paths.

2. An apparatus unit as described in claim 1, wherein the length of saidblades is greater than half the length of the vessel.

3. An apparatus unit as described in claim 2, wherein said pluralitycomprises at least three blades.

4. An apparatus unit as described in claim 1, wherein said vessle is anupright vessel and said support and plane are horizontal;

and further including a removable lid closing the top of the vessel,

an air supply pipe opening through the lid into the vessel, and

a discharge tube extending through the lid toward the vessel bottom,

whereby the unit constitutes a coreor mold-shooting apparatus,discharging a finished composition mixture while oscillating and underan air pressure differential between the air supply pipe and an outerend of the discharge tube.

5. An apparatus unit as described in claim 1, wherein said vessel is anupright cylinder on a horizontal support, and said curve is a circleconcentric with the vessel axis, and further including a cylindricalmember coaxial within the vessel and joined to and extending upwardlyfrom the upper ends of the blades.

6. Apparatus comprising a plurality of successively adjacent apparatusunits as described in claim 5 sharing a common support and wherein eachsaid cylindrical member at its upper end has a lateral discharge openingand bears a lateral discharge conduit at said opening for dischargingand conveying mixed material into the space between the wall and themixing device of the succeeding adjacent vessel, and from a last unit toserve as the apparatus discharge for finished mixed material;

and thereby being adapted to serve as a continually fed and continuallydischarging mixing apparatus.

7. Apparatus as described in claim 6, comprising two said pluralities ofapparatus units, arranged in two respective rows on a said commonsupport, and with the discharge conduits of the last units of said rowsdischarging into a common subsequent orbiting mixer vessel.

8. An apparatus unit as described in claim 1, wherein the blades of saidset are spaced and arranged on a circle as said closed curve,

and within said set there is located a second set of similar bladesarranged along a closed curve concentric with the said circle, anddisposed in the range between tangential and perpendicular to the curve.

9. An apparatus unit as described in claim 1, including as said vessel,an upright cylindrical vessel with the plane ofoscillation perpendicularto the vessel axis; and

a plurality of said mixing devices located on and spaced along a circlewhich is coaxially spaced within the cylindrical wall of the vessel.

10. Apparatus as described in claim 9, including a damming partitionextending upwardly from the bottom to the top of the vessel andprojecting from the vessel cylindrical wall inwardly between twoadjacent said mixing devices;

lateral discharge conduit means associated with a lateral opening in theupper part of the vessel wall adjacent to one side of the partition; and

feed conduit means on the other side of said partition for supplying tosaid vessel material to be mixed;

whereby said apparatus is adapted to operate as a continuously fed anddischarging mixer.

11. Apparatus as described in claim 1, wherein said vessel comprises agenerally horizontal trough of elongated oblong plan configuration andhaving a longitudinal center line; and

said blades are disposed horizontally extending longitudinally of thetrough and substantially over the length thereof; and arranged on acircle as said closed curve;

said trough being oscillatable orbitally about an oscillation axisparallel to its longitudinal center line.

12. Apparatus as described in claim 11, wherein said trough has a bottomrounded in transverse cross section, and a closed configuration;

said mixing device has the blades thereof spaced more widely at the topof the set;

and including material feed conduit means opening into one end of saidtrough, and a lateral discharge conduit opening from the other end ofthe trough; whereby the apparatus is adapted to serve as a continuousmixer. 13. Apparatus as described in claim 1, wherein said vessel is anupright cylindrical vessel, and has said mixing device disposedconcentrically therein with said blades longitudinally upright. 14. Anapparatus comprising a plurality of apparatus as described in claim 13with the vessels thereof arranged on a common support successively in acircle and with the cylindrical walls of successively adjacent vesselsintersecting at the regions of intersections affording communicatingopenings between at least all but one adjacent pair of vessels, andthereby forming a larger generally annular material containing space.

15. An apparatus as described in claim 14, including one pair ofadjacent vessels which at the region of intersection have a common wallportion blocking communication therebetween', a lateral opening andassociated discharge conduit extending outwardly from said annularmaterial containing space from one vessel of said pair; and supplyconduit means feeding at least into the other vessel of said pair. 16.Apparatus as described in claim 1, wherein said vessel is an uprightcylindrical vessel: said blades are each curved at its outer end to turnback inward to the next in the direction of orbital movement therebyconjointly to form a plurality of generally cylindrical mixing chambers,the inner end of each said blade leading into a central space surroundedby said mixing chambers, and

defining with an adjacent blade a narrow elongated vertical slot openingfrom a respective chamber to said central space;

said central space being closed at the top and having a bottom wallaperture as a discharge outlet of the apparatus;

whereby with different materials to be mixed fed to successivelyalternatingly located chambers, the apparatus delivers from said bottomwall aperture a composition of said materials mixed in said centralspace, upon orbital oscillation of the apparatus.

17. Apparatus as described in claim 16, wherein the said dischargeoutlet comprises a bottom wall central opening surrounded by adownwardly con vergent funnel-like flange.

18. Apparatus as described in claim 1, wherein inward channels, from thecircumferential region exterior of the mixing device to the interiorregion thereof, as channels defined between mutually adjacent blades,are of relatively different width. l IF

1. An orbitally oscillating mixing apparatus unit for fluent soldimaterial, such as foundry molding materials, comprising: a supportmounted for, and driven with, an orbital oscillation in a plane, avessel secured on the support for oscillation therewith, and providing amixing space enclosing wall substantially perpendicular to the plane ofsupport oscillation, a plurality of blade-like elements secured as a setto the vessel to move therewith, and elongated in direction away fromthe support, and located and spaced along a closed conic curve the planeof which is parallel to the plane of oscillation, the widths of saidblades having similar angular dispositions between radial and tangentialto the curve, and slanted outwardly toward the direction of orbitaloscillation, said blades thereby forming a set of somewhat impeller-likeconfiguration cooperating in action on material as a mixing device,whereby, in addition to a main flow induced in material in the vesseltending to circulate in a path along the enclosing wall oppositely tothe orbital oscillation direction, the mixing device acts to set up atleast a second flow circulating within the device and having also acomponent perpendicular to the plane of oscillation, by each bladedeflecting material, from a portion circulating in the main flow path,inwardly to a path of recombination within the mixing device and with aconstant exchange of material between the two circulating flow paths. 2.An apparatus unit as described in claim 1, wherein the length of saidblades is greater than half the length of the vessel.
 3. An apparatusunit as described in claim 2, wherein said plurality comprises at leastthree blades.
 4. An apparatus unit as described in claim 1, wherein saidvessle is an upright vessel and said support and plane are horizontal;and further including a removable lid closing the top of the vessel, anair supply pipe opening through the lid into the vessel, and a dischargetube extending through the lid toward the vessel bottom, whereby theunit constitutes a core- or mold-shooting apparatus, discharging afinished composition mixture while oscillating and under an air pressuredifferential between the air supply pipe and an outer end of thedischarge tube.
 5. An apparatus unit as described in claim 1, whereinsaid vessel is an upright cylinder on a horizontal support, and saidcurve is a circle concentric with the vessel axis, and further includinga cylindrical member coaxial within the vessel and joined to andextending upwardly from the upper ends of the blades.
 6. Apparatuscomprising a plurality of successively adjacent apparatus units asdescribed in claim 5 sharing a common support and wherein each saidcylindrical member at its upper end has a lateral discharge opening andbears a lateral discharge conduit at said opening for discharging andconveying mixed material into the space between the wall and the mixingdevice of the succeeding adjacent vessel, and from a last unit to serveas the apparatus discharge for finished mixed material; and therebybeing adapted to serve as a continually fed and continually dischargingmixing apparatus.
 7. Apparatus as described in claim 6, comprising twosaid pluralities of apparatus units, arranged in two respective rows ona said common support, and with the discharge conduits of the last unitsof said rows discharging into a common subsequent orbiting mixer vessel.8. An apparatus unit as described in claim 1, wherein the blades of saidset are spaced and arranged on a circle as said closed curve, and withinsaid set there is located a second set of similar blades arranged alonga closed curve concentric with the said circle, and disposed in therange between tangential and perpendicular to the curve.
 9. An apparatusunit as described in claim 1, including as said vessel, an uprightcylindrical vessel with the plane of oscillation perpendicular to thevessel axis; and a plurality of said mixing devices located on andspaced along a circle which is coaxially spaced within the cylindricalwall of the vessel.
 10. Apparatus as described in claim 9, including adamming partition extending upwardly from the bottom to the top of thevessel and projecting from the vessel cylindrical wall inwardly betweentwo adjacent said mixing devices; lateral discharge conduit meansassociated with a lateral opening in the upper part of the vessel walladjacent to one side of the partition; and feed conduit means on theother side of said partition for supplying to said vessel material to bemixed; whereby said apparatus is adapted to operate as a continuouslyfed and discharging mixer.
 11. Apparatus as described in claim 1,wherein said vessel comprises a generally horizontal trough of elongatedoblong plan configuration and having a longitudinal center line; andsaid blades are disposed horizontally extending longitudinally of thetrough and substantially over the length thereof; and arranged on acircle as said closed curve; said trough being oscillatable orbitallyabout an oscillation axis parallel to its longitudinal center line. 12.Apparatus as described in claim 11, wherein said trough has a bottomrounded in transverse cross section, and a closed configuration; saidmixing device has the blades thereof spaced more widely at the top ofthe set; and including material feed conduit means opening into one endof said trough, and a lateral discharge conduit opening from the otherend of the trough; whereby the apparatus is adapted to serve as acontinuous mixer.
 13. Apparatus as described in claim 1, wherein saidvessel is an upright cylindrical vessel, and has said mixing devicedisposed concentrically therein with said blades longitudinally upright.14. An apparatus comprising a plurality of apparatus as described inclaim 13 with the vessels thereof arranged on a common supportsuccessively in a circle and with the cylindrical walls of successivelyadjacent vessels intersecting at the regions of intersections affordingcommunicating openings between at least all but one adjacent pair ofvessels, and thereby forming a larger generally annular materialcontaining space.
 15. An apparatus as described in claim 14, includingone pair of adjacent vessels which at the region of intersection have acommon wall portion blocking communication therebetween; a lateralopening and associated discharge conduit extending outwardly from saidannular material containing space from one vessel of said pair; andsupply conduit means feeding at least into the other vessel of saidpair.
 16. Apparatus as described in claim 1, wherein said vessel is anupright cylindrical vessel; said blades are each curved at its outer endto turn back inward to the next in the direction of orbital movementthereby conjointly to form a plurality of generally cylindrical mixingchambers, the inner end of each said blade leading into a central spacesurrounded by said mixing chambers, and defining with an adjacent bladea narrow elongated vertical slot opening from a respective chamber tosaid central space; said central space being closed at the top andhaving a bottom wall aperture as a discharge outlet of the apparatus;whereby with different materials to be mixed fed to successivelyalternatingly located chambers, the apparatus delivers from said bottomwall aperture a composition of said materials mixed in said centralspace, upon orbital oscillation of the apparatuS.
 17. Apparatus asdescribed in claim 16, wherein the said discharge outlet comprises abottom wall central opening surrounded by a downwardly convergentfunnel-like flange.
 18. Apparatus as described in claim 1, whereininward channels, from the circumferential region exterior of the mixingdevice to the interior region thereof, as channels defined betweenmutually adjacent blades, are of relatively different width.